It could be the ultimate Christmas present for anyone who can afford the stellar price tag.

Nasa has announced plans to sell off its space-shuttle fleet for US$42 million apiece, postage and packing included, when the orbiters stop flying in 2010.

Selling off its three remaining shuttles would bring in much-needed dollars to the hard-up US space agency, which is already facing a budget deficit for the next-generation Ares rockets that will return astronauts to the moon.

The advertised price is just the starting figure for any one of the orbiters Discovery, Atlantis or Endeavour, which have flown a total of 86 missions into space since 1984. Included is the minimum US$6 million cost of stripping a shuttle of toxic and other hazardous materials, preparing it for travel and flying it to an airport of the buyer's choosing.

But as an agency of the US government, Nasa insists it will not sell its most prized assets to just anybody. So far, it is approaching only educational institutions, science museums and 'other appropriate organisations' to gauge interest, and assess the size of their chequebooks.

'Nasa is keenly aware of the essential value of these key assets to the space programme's rich history,' an official says in a 'request for information' document that seeks ideas for the public display of the ageing orbiters after their retirement.

'The agency is therefore committed to making placement decisions that are determined to be in the best interest of the American taxpayer. Special attention will be paid to ensuring they will retire to appropriate places.'

Only US citizens will be eligible to purchase and display the shuttles, which will be sold with all space- worthy fittings and fixtures except the main engines, thwarting any potential buyers' plans for an intergalactic mission of their own.

Interested parties must also promise to display the spacecraft in a climate-controlled indoor location.

Nasa's end-of-season sale includes more than just the spacecraft. Six main shuttle engines will be available for separate purchase for up to US$800,000 each, excluding transport costs.

Only two of the shuttles are likely to be sold, with the third expected to remain in government hands, possibly on display in Washington.